Laser toner cartridges are manufactured to a high degree of precision necessary for proper operation and good printed image quality. Of importance to the proper operation of a laser toner cartridge is the maintenance of alignment and orientation of its various components. Original equipment manufactured (OEM) cartridges achieve the rigidity necessary to maintain the alignment and orientation of components, in substantial part by ultrasonically welding sections of the toner, or process, cartridge together.
The process of repairing or remanufacturing such a cartridge requires that the cartridge be disassembled and that the hopper section of the cartridge, which holds the toner, be separated from the magnetic roller section, which contains the magnetic or developer roller and other components. When the hopper and roller sections have been separated and are subsequently joined back to each other, or to corresponding sections of other previously depleted cartridges, precise alignment and orientation of performance critical components are necessary during the remanufacturing and reassembly process, particularly between the roller and the hopper sections.
A conventional approach to this problem is careful manual alignment and fitting of the two sections together, with or without the aid of a positioning jig, and then manual securing of the sections together with a number of metal clips. Alternatively, the sections maybe fastened together with adhesive or glue. These techniques, while generally effective, suffer from a number of deficiencies or drawbacks.
The most common drawback is that the dimensional height of the roller and/or hopper section has been changed when compared to the cartridge's original specifications. Another drawback is that both metal clips and adhesives are consumables, and their use increases production costs and final product cost of manufacture. Another significant drawback is that manual reassembly is quite labor intensive, as well subject to human error and variations in quality. In reassembly with adhesive or glue, a period of a few, to several minutes is required for bonding to take place and during which time precise alignment must be maintained. An additional drawback to the use of metal clips to reassemble the cartridge sections is that the rigidity imparted by the original ultrasonic weld is difficult to achieve, and over the working life of a conventionally reassembled cartridge the clips may loosen or become disengaged entirely. In such an event, as a result of a loss of proper alignment of the hopper seal and/or roller section, excessive toner may accumulate on the roller with the result being an excessive amount of toner on the roller. This excess toner is then transferred to the photoconductive printing drum and then to the printer paper, thereby resulting in unsatisfactory finished product quality. Further, disengagement of a metal clip may permit toner to leak from the cartridge. In many printing devices, such as printers, facsimile machines or copiers, the path of the paper through the printing device passes nearby to the edge of the toner cartridge where the metal clips have been installed. Paper jams can occur if a loose metal clip projects into the paper path.
Original equipment laser toner cartridge sections are typically joined together by an ultrasonic welding process. A primary impediment to the use of ultrasonic welding in the rejoining of previously used or spent cartridge sections has been the absence of an energy director element, usually due to the destruction of the energy director material when the spent cartridge is disassembled by sawing the cartridge at the plane where the original roller section and hopper section were joined by the initial ultrasonic weld.
As is understood in this field, an energy director element is a material that is typically in the form of a ridge or bump, extending slightly above the surface of the surrounding area and contacting the surface(s) to be welded. It is typically, originally molded on the surface of either the roller section or the hopper section for original equipment cartridges, and is made typically of an organopolymeric material such as ABS or polystyrene. The energy director is of the same material as the hopper and roller sections of the cartridge and is formed in the mold in which the plastic component is created. The energy director material or element is in direct contact with the surface to be ultrasonically welded. During the ultrasonic welding process, it is the energy director element that is first melted or fused as a result of the friction created between the two surfaces to be welded by the ultrasonic vibrations. It is the melting or fusing together of the surfaces to be bonded, at the location of the energy director element that, upon cooling, solidifies and seals the hopper section to the roller section. The energy director element is often largely or entirely consumed in the original manufacture of a new toner cartridge. Hence, upon separation of the hopper and roller sections at the location of the original ultrasonic weld in preparation for a remanufacturing process, insufficient residual energy director might remain to accomplish rewelding to join or reseal a previously spent hopper to a previously spent roller section. The present invention is directed to solving these problems by providing a reassembled toner cartridge and method of manufacture in which previously spent hopper sections and previously spent roller sections may be ultrasonically welded to previously spent or to new complementary sections with the use of ancillary energy director material placed between the two sections to be ultrasonically welded together.